EP1621459B1 - Aircraft drain system - Google Patents

Abstract

An aircraft has an in-flight fuel or water dumping valve that is operated as required and incorporates a heating element to prevent the formation of ice. Prior to discharge the liquid or gas fuel is pre-heated by a coolant that derives its heat energy from an on-board thermal or electro-chemical process e.g. from a fuel cell. The coolant may also be employed in a thermal or electro-chemical process.

Description

The present invention relates to discharge devices for aircraft. In particular, the present invention relates to a discharge device for an aircraft, an aircraft, comprising a corresponding discharge device, and a method.

At cruising altitudes of today's commercial aircraft, outside temperatures of up to - 60 ° C prevail. Water-containing fluids from the galley area or from the wash basins as well as from the cargo space drainage, which are left without special heating to the outside, would immediately freeze or form lumps of ice and thus clog the outlet pipe. For this reason, today's drainage nozzles (drain masts) are heated.

Outlet nozzles or drainage devices according to the prior art, for example, have the disadvantage that they have an increased energy requirement for heating the liquid to be drained off. This energy must be provided by the on-board supply. Accordingly, extra heating elements are provided in known drain devices, which also can lead to an additional space requirement.

US 5,655,732 discloses a device for sewage drainage for aircraft and for heating a drainage pipe. The heating air is taken from a thermal process in the engine.

It is an object of the present invention to provide an improved discharge device for aircraft, which is characterized in particular by space saving and energy efficiency.

The above object is achieved with a discharge device having the features of claim 1.

The liquids to be drained may be, for example, gray water, ie slightly contaminated water, eg. B. sink and galley sink from the kitchen area of the aircraft act. The gases to be vented may be For example, exhaust gases that result from a thermal process or electrochemical process aboard the aircraft, such as a fuel cell process act.

In this way, the drained liquids or gases can be heated within the discharge device, so that icing or the formation of ice lumps is avoided. Furthermore, outside air can be introduced into the aircraft via the discharge device. The outside air may for example be supplied to a thermal process or electrochemical process on board the aircraft or to a fuel cell process. Thus, advantageously, a discharge device is provided which is usable not only for discharging liquids or gases from the aircraft but also for introducing outside air into the aircraft.

According to the present invention, the coolant is supplied to a fuel cell process aboard the aircraft. In this case, the coolant is heated by the Brennstoftzellenprozeß and is used for cooling of the fuel cell process.

Advantageously, therefore, the waste heat, which arises from a fuel cell process on board the aircraft and anyway must be dissipated to the outside, be discharged through the housing of the discharge device. At the same time, the heating heat required for the discharge device is provided in order to avoid freezing of the liquid discharged through the discharge device or the gases discharged at cruising altitude or in other cold ambient conditions.

According to a further embodiment of the present invention, the discharge device further comprises a pressure control unit, wherein the tube has an end portion and for introducing air into the aircraft with its end portion at an angle of 0 ° to about 45 ° to the direction of flight, so that in the tube created by the airspeed dynamic pressure arises. Here, the back pressure is adjustable by the pressure control unit.

Advantageously, by the arrangement of the tube at an angle between about 0 ° to about 45 ° to the direction of flight provides the opportunity to absorb outside air under a correspondingly high back pressure. Possibly. For example, the dynamic pressure can subsequently be regulated down accordingly by the pressure regulating unit, so that the absorbed outside air can then be supplied to a fuel cell process on board the aircraft, for example under a desired process pressure and at a desired temperature.

According to a further embodiment of the present invention, the discharge device further comprises an air compressor and a switching valve, wherein the dynamic pressure can be generated by the air compressor and wherein the air compressor can be switched to cabin air via the switching valve.

Advantageously, the dynamic pressure necessary for supplying the onboard fuel cell can thus also be generated when the airspeed is not high enough or when the aircraft is standing on the ground. Furthermore, it is possible in this case that the air compressor uses the cabin air, so that a corresponding preheating can be at least partially saved.

According to a further embodiment of the present invention, the discharge device further comprises a cooling surface, wherein the coolant is coolable by the cooling surface before it is supplied to the thermal process or electrochemical process.

Thus, it is advantageously possible to use the low outside temperature to further cool the coolant. The corresponding cooling takes place here within the discharge device using the cooling surface, so that additional components are not required. Thus, on the one hand skillful utilization of low outdoor temperatures and on the other hand, a space-saving overall arrangement possible.

According to a further exemplary embodiment of the present invention, the liquid to be drained is greywater from the on-board operation of the aircraft and, in the case of the gases to be discharged, exhaust air from the thermal process or electrochemical process on board the aircraft.

Advantageously, thus four functions are integrated in one arrangement, namely the heating of the drain mast or the pipe, the cooling of a lying inside the airframe thermal or electrochemical process, such. As that of a fuel cell, the supply of this process with outside air and the discharge of excess gases from this process. In addition, the arrangement has the advantage that for the cooling function does not have to intervene in the cell structure of the aircraft, ie that no additional radiator or air induction for cooling purposes on the outer skin of the aircraft is necessary. A significant increase in air resistance can thus be avoided.

According to a further embodiment of the present invention, the discharge device further comprises an electric heating device, wherein the tube is additionally heated by the electric heater.

Thus, it is advantageously possible to supply additional heating energy to the pipe. This may be necessary, for example, when the fuel cell on board the aircraft does not produce enough thermal excess energy to provide a correspondingly sufficient heating of the discharge pipe.

According to a further exemplary embodiment of the present invention, a heat pumping process can be connected, which increases the heating power for heating the pipe or the cooling power for cooling the thermal or electrochemical process.

Advantageously, the heat pump process can be interposed between the cooling medium, so that the heaters of the drain pipes and, associated therewith, the flow temperature of the cooler are raised to a higher temperature level. Thereby, for example, the efficiency of the fuel cell or the discharge rate of the liquid or gases through the pipe can be increased.

According to a further exemplary embodiment of the present invention, a method is provided for discharging liquids or gases from an aircraft or for introducing air into the aircraft through a discharge device, wherein the discharge device comprises a pipe and a coolant and the method comprises heating the pipe through the Coolant or by a heat exchanger, wherein the tube for discharging liquids or gases from the aircraft or for introducing air into the aircraft is usable.

In this way, the drained liquids or gases or the supplied outside air can be heated within the discharge device, so that icing or the formation of ice lumps is effectively avoided.

Other objects, embodiments and advantages of the invention will become apparent from the dependent claims.

In the following, preferred embodiments of the present invention will be described with reference to the figures.

Fig. 1 shows a schematic representation of a cooling / heating process according to an embodiment of the present invention.

Fig. 2 shows a schematic representation of a discharge device according to an embodiment of the present invention.

In the following description of the figures, the same reference numerals are used for the same or similar elements.

Fig. 1 shows a schematic representation of a cooling / heating process according to an embodiment of the present invention. As Fig. 1 can be seen, the discharge device 100 according to the invention is an integral part of the cooling or heating processes, such as on board an aircraft, for example, when draining Gray water or gases from the aircraft or during the introduction of outside air into the aircraft, are required. Here, the discharge device 100 essentially consists of a series of heat exchangers 16, 17, 18, 19, 20, which are characterized by advantageous use of the increased temperature of the exhaust air of a thermal or electrochemical process on board the aircraft and the relatively low temperature outside the aircraft , Corresponding heat exchangers are well known in the art and will not be shown in detail here. It should be noted, however, that here is a variety of different systems suitable for use as a heat exchanger. It is important here that heat from the coolant in the circuit 5, 6 is discharged to the corresponding tubes 23, 24, 28, 29, 30, 31, 32, 33 or the gases or liquids contained therein (or vice versa).

Heat exchanger 16 here is a heat exchanger for a condenser through which the exhaust air 24 from the thermal or electrochemical process 22, which may be, for example, a fuel cell process, is condensed. The resulting condensate 103 is discharged. In this case, an energy carrier 27 is supplied to the thermal or electrochemical process 22, which is subsequently converted, for example, essentially into energy, oxygen and fresh water, with the admixture of a supply air 25. The resulting excess process heat can be dissipated via exhaust air 24. The heat energy of the exhaust air 24 is partially fed via heat exchanger 16 into the coolant circuit 5, 6.

The coolant circuit 5, 6 in this case consists of a cooling-Heizmediumrücklauf 5 and a cooling-Heizmediumvorlauf 6. The cooling medium or heating medium, which may be, for example, a corresponding liquid is transported within a pipe or a piping system 5, 6 ,

Via the heat exchanger 17, the thermal process 22 can be cooled at the appropriate location and at a corresponding time in the form of process cooling 23. In this case, on the one hand, the efficiency of the thermal or electrochemical process can be increased. On the other hand, the process cooling 23 advantageously leads to an increase in the temperature in the flow 6 of the cooling circuit, so that the coolant can now be used for heating water or air.

The heating or cooling liquid is circulated by a circulation pump 14. By adjusting the pump speed as well as the interconnection with another cooler / heater, the cooling or heating capacity can be regulated with appropriate dimensioning. The resulting in the thermal or electrochemical process 22 exhaust gases 11 are derived via corresponding exhaust pipes 28, 29 from the fuel cell assembly or the reactor 22. So that the exhaust gases 11 do not freeze when being discharged from the aircraft or the water contained therein does not form any icing of the exhaust pipe 29, the exhaust gases can be heated via heat exchanger 18. Furthermore, it is possible that in addition to the coolant circuit side heating of the exhaust gases via heat exchanger 18, a further heating 12 is provided for the discharge pipes 29. This may be, for example, an electric heater 121. An icing of the exhaust pipes 29 is thus effectively prevented.

Furthermore, a heat exchanger 19 is provided, which uses the heat provided by the coolant circuit 5, 6 to warm up to be discharged greywater 7 from the on-board operation before discharging from the aircraft or to the pipes 30, 31 for transporting the gray water from the aircraft before icing protect. In addition to the heat exchanger 19, the greywater discharge pipes 31 can be electrically heated via heaters 12 be so that even with an insufficient amount of heat, which is provided via the coolant circuit 5, 6, icing of the greywater outlet 10 is prevented. Heaters 12 and 121 may also be combined into a single heater.

Furthermore, a heat exchanger 20 is provided, which is provided for heating ram air. The ram air is outside air 9, which is supplied via a ram air line 32 from the outside into the discharge device 100. The tube 9 for introducing air into the aircraft has with its end portion at an angle of about 0 ° to about 45 ° to the direction of flight, so that in the tube 9 caused by the airspeed dynamic pressure. The thus collected ram air is subsequently fed via ram air line 32 to the heat exchanger 20 and brought there to a corresponding process temperature. Subsequently, the heated ram air via pipe 33 is supplied to a switching valve 26, via which additionally or alternatively to the ram air cabin air can be supplied.

Subsequently, the cabin air supplied via line 34 or the line 33 supplied ram air can be further compressed by the compressor 15. This may be necessary in particular if the travel speed of the aircraft is insufficiently high or the aircraft is on the ground, so that sufficient ram air pressure can not be generated. The compressor 15 may be, for example, an electric compressor, which receives its energy from onboard sources.

About the downstream pressure valve 21, the pressure of the supplied ram air or cabin air is controlled accordingly. Subsequently, the inventively warmed up Outside air as supply air 25 are supplied to the thermal or electrochemical process 22.

As Fig. 1 it can be seen, the discharge device is partially disposed on the inside 101 of the aircraft and partially on the outside 102 of the aircraft. The boundary between inner region 101 and outer region 102 is defined here by the fuselage 1 and its outer skin 2. The part of the discharge device 100 arranged in the outer region 102 of the aircraft is at least partially enclosed by the outer skin 3 of the discharge device 100.

For further cooling down of the refrigerant flowing in the cooling circuit 5, 6, after the coolant has passed through the heat exchangers 16, 17, 18, 19 and 20, cooler 4 is used. The radiator 4 is in this case in the outer region 102 of the aircraft and has direct contact with the outside air. Thus, effective cooling is ensured when the aircraft is at an appropriate altitude or when the outside temperature is correspondingly low.

Fig. 2 shows a schematic representation of a discharge device according to an embodiment of the present invention. As in Fig. 2 To recognize, the discharge device 100, which is arranged to a substantial extent in the outer region of the aircraft 1, an outer skin 3 with a radiator with cooling fins 4. Furthermore, the discharge device 100 greywater drain pipes 7, 31, which serve to drain liquids from galleys and hand basins. These tubes 7, 31 are surrounded by a liquid heater 37, wherein the feed of the heating fluid at the outlet end 35 of the tube 31 and the return at the upper end 36 of the liquid heater 37 is arranged.

The liquid heater 37, which comprises heat exchangers 18, 19, 20, is additionally surrounded by an electric heater (not shown in FIG Fig. 2 ) to ensure the heating function even with inactive or inadequate liquid heating.

The flow 6 of the liquid heater 37 is from a cooling circuit of a thermal or electrochemical process (s. Fig. 1 ) fed inside the aircraft. This can be, for example, a fuel cell process, in which the cell cooling or the water condensation is realized by this cooling circuit. The return 5 of the drain-mast-side liquid heater 37 is guided by a cooler 4 arranged on the outer skin 3 of the drain-mast housing. Thus, an efficient cooling of the coolant in the return 5 is given. The cooling liquid of the return 5 is thus cooled down to the required cooling temperature of the internal thermal or electrochemical process.

Furthermore, the heating or cooling liquid by a circulating pump (not shown in Fig. 2 ) pumped around. By adjusting the pump speed as well as the interconnection with another cooler / heater, the cooling or heating capacity can be regulated with appropriate dimensioning.

In addition, a heat pumping process between the internal thermal or electrochemical process to be cooled and the heater of the drain mast 100 may be switched to increase the heater power on the drain mast side and the cooling power inboard. Thus, for example, the efficiency of a fuel cell assembly can be optimized inside the aircraft.

At the front of the drain mast 100 there is a ram air opening 9 with a pipe 32 behind it, through which the pipes for the thermal or electrochemical process (see reference numeral 22 in FIG Fig. 1 ) and brought to process temperature by liquid heaters 37.

Furthermore, at the rear of the drain mast 100 there is a pipe outlet 11 for discharging possibly excess gas from a fuel cell process (so-called purge process). Since this excess gas may contain moisture, it is necessary that this pipe 29 is heated.

Thus, with the discharge device 100 described waste heat, which must be discharged from a thermal or electrochemical process, such as a fuel cell process, on board the aircraft to the outside, discharged through the housing of the so-called. Drain mast and at the same time for the drain mast 100th required heating heat to prevent freezing of the drained through the drain mast 100 liquid during the flight or other cold environmental conditions.

The advantages here are the integration of four functions in one arrangement, namely the heating of the drain mast 100, the cooling of a lying inside the airframe thermal or electrochemical process, such. As that of a fuel cell, the supply of this process with outside air and the discharge of excess gases from this process. In addition, the arrangement has the advantage that for the cooling function does not need to be intervened in the cell structure of the aircraft, ie that no additional radiator or no air introduction for cooling purposes on the outer skin of the Plane is necessary. A significant increase in air resistance can thus be avoided.

An intake of the air required by a fuel cell via the drain mast by means of pitot tube 32 also has the advantage that the ram air can be preheated with the cooling / heating medium in countercurrent, to then be provided to the fuel cell with optimum operating temperature.

The invention is not limited in its execution to the preferred embodiments shown in the figures. Rather, the invention is limited only by the terms of the claims.

In addition, it should be noted that "comprising" does not exclude other elements or steps and "a" or "an" does not exclude a plurality. Reference signs in the claims are not to be considered as limitations.

Claims (10)

1. A drain system for an aircraft, comprising:

   a fuel cell;

   a mast (30, 31) for draining liquids or gases from the aircraft;

   a pipeline (32) for delivering ram air to the fuel cell process of the fuel cell;

   a coolant;

   wherein the drain system is adapted for heating the mast (30, 31) and the pipeline (32) by means of the coolant;

   wherein the coolant is delivered to the fuel cell process of the fuel cell;

   wherein the fuel cell process is adapted for heating the coolant;

   wherein the coolant is used for cooling the fuel cell process; and

   wherein the coolant is located inside a coolant circuit (5, 6).
2. The drain system of claim 1, further comprising a heat exchanger (19), wherein the mast (30, 31) is adapted for being heated by the heat exchanger (19).
3. The drain system of one of claims 1 to 2, furthermore comprising:

   a pressure control unit (21);

   wherein the pipeline (32) has an end region;

   wherein the pipeline (32) is angled relative to the aircraft heading by an angle between approximately 0° and 45° in order to draw air into the aircraft, namely such that the air speed causes ram pressure to build up in the pipeline (32); and

   wherein the dynamic pressure can be a regulated with the pressure control unit (21).
4. The drain system of one of claims 1 to 3, furthermore comprising:

   a cooling surface (4), adapted for cooling the coolant with the aid of the cooling surface before it is delivered to the fuel cell process.
5. The drain system of one of claims 1 to 4,
   wherein the liquid to be drained consists of gray water accumulated on board the aircraft during its operation; and
   wherein the gases to be discharged consist of exhaust air produced by the fuel cell process.
6. The drain system of one of claims 1 to 5,
   an electric heater (12);
   wherein the mast (30, 31) can be additionally heated by means of the electric heater (12).
7. The drain system of one of claims 1 to 6, further comprising a device for additionally switching on a heat pump process,
   wherein the heat pump process increases a heating power for heating the mast (30, 31) or a cooling power for cooling the thermal or electrochemical process (22).
8. An aircraft comprising a drain system of one of claims 1 to 7.
9. Aircraft of claim 8, further comprising an aircraft cabin comprising cabin air; the drain system comprising:

   an air compressor (15) and;

   a change-over valve (26);

   wherein ram air can be further compressed with the aid of the air compressor (15); and

   wherein the air compressor (15) can be changed over to cabin air by means of the change-over valve.
10. A method for draining liquids or gases from an aircraft by means of a drain system that contains a mast (30, 31) and a coolant, with said method comprising the following steps:

    draining liquids or gases from the aircraft by means of the mast (30, 31);

    delivering ram air to the fuel cell process of a fuel cell by means of a pipeline (32); delivering the coolant to the fuel cell process on board of the aircraft;

    heating the coolant by means of the fuel cell process;

    cooling the fuel cell process by means of the coolant;

    heating the mast (30, 31) and the pipeline (32) by means of the coolant;

    wherein the coolant forms a coolant circuit between the fuel cell process, the mast (30, 31) and the pipeline (32).

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